Conic Sections Question 148
Question: If PSQ is the focal chord of the parabola $ y^{2}=8x $ such that $ SP=6 $ . Then the length SQ is
Options:
A) 6
B) 4
C) 3
D) None of these
Show Answer
Answer:
Correct Answer: C
Solution:
Since the semi-latus rectum of a parabola is the harmonic mean between the segments of any focal chord of a parabola, therefore $ SP,4,SQ $ are in H.P.
$ \Rightarrow 4=2.\frac{SP.SQ}{SP+SQ}\Rightarrow 4=\frac{2(6)(SQ)}{6+SQ}\Rightarrow SQ=3 $ .
BETA
